JP3540541B2 - Swing hydraulic excavator - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a hydraulic excavator provided with a traveling body and a revolving body that is pivotably mounted on the traveling body. For example, the boom swings left and right at a front end side position of the revolving body in order to dig a gutter. It relates to a swing type hydraulic excavator that can be used.
[0002]
[Prior art]
2. Description of the Related Art In recent years, in order to enable work in narrow places, small turning hydraulic excavators having a small turning radius and capable of turning a work front have been spotlighted. It is an essential function of the small turning hydraulic excavator that a ditch can be dug near the side of the vehicle width without changing the vehicle body position. Therefore, there are an offset type and a swing type.
[0003]
Examples of the offset include the following (1), and examples of the swing type include the following (2) and (3).
(1) JP-A-3-255241
In this known technique, an arm is provided at an end of the boom, which is capable of rotating left and right in an offset manner, and a bucket arm which is capable of swinging up and down with respect to the offset arm while maintaining parallelism with the boom. A vertical groove is formed in the upper cover to prevent interference between the boom and the upper cover that covers most of the area other than the cab when the boom is swung up to the maximum. Is disclosed.
(2) JP-A-5-125743
This known technique discloses a swing type excavator in which a boom can swing left and right around a swing post at a position on a front end side of a revolving superstructure.
(3) JP-A-7-243223
According to this known technique, in a swing hydraulic excavator similar to the above (2), a boom can swing up and down with respect to a swing post, and a boom can swing up and down with respect to the lower boom. A structure is disclosed in which a two-piece boom is provided with an upper boom and an opening angle adjusting means for changing an angle between the lower boom and the upper boom according to the swing angle of the lower boom.
[0004]
[Problems to be solved by the invention]
By the way, generally, parts other than the operator's cab on the turning frame of a hydraulic excavator are covered with an upper cover, and since equipment such as a motor, a hydraulic pump, and a tank are housed inside the upper cover, the upper cover is provided. Requires a minimum volume that can accommodate those devices.
[0005]
In the offset type hydraulic excavator of the above-mentioned known technique (1), a vertical groove into which the back of the boom enters when the boom is swung up rearward is provided in the upper cover. But,
In the offset type, since the boom simply rotates up and down, a decrease in the volume of the upper cover due to the vertical groove is small, and necessary equipment can be stored in the upper cover. In addition, since the boom can be largely tilted rearward, the front turning radius can be reduced in the front minimum turning posture.
[0006]
However, in the offset type, a complicated parallel link mechanism and a cylinder for driving the parallel link mechanism are provided on the upper part (upper boom) of the work front. For this reason, the weight of the work front increases, and the following problems occur.
(1) The weight of the work front becomes very heavy, and depending on the posture of the work front, the position of the center of gravity is biased toward the front end, so that the stability is deteriorated.
(2) Since the weight of the work front is heavy, the counterweight also needs to be heavy. As a result, the excavator weighs as much as one class higher than a standard excavator with a weight of the entire excavator that is not an offset type, and the transportation cost is increased.
(3) Since the weight of the body increases, it is necessary to increase the output of the prime mover, which increases the manufacturing cost and the running cost.
In the offset method, the arm and the bucket are offset in parallel to the boom, so that the following problem occurs.
(4) A vertical pin is used for the connection between the lower boom and the upper boom, and when the crushing operation is performed by a front attachment such as a breaker that generates a large impact force or vibration in the excavation direction, the vertical pin is bent. It is easy to cause damage.
(5) When digging deep gutters, the lower part of the parallel link mechanism and the ground surface may interfere with each other, so that the digging depth cannot be made larger than that of a standard machine not using the offset method.
(6) Due to the complicated parallel link mechanism, the manufacturing cost is increased and the maintainability is deteriorated.
(7) When the arm and the bucket are offset to the opposite side from the cab, the boom obstructs the field of view, so that it is difficult to see the excavation position from the cab.
In contrast to the offset type excavator, the swing type excavator as described in (2) and (3) does not use a complicated parallel link mechanism at the upper part of the work front, so that the weight increase as in the offset type is not possible. And there is no problem due to the offset movement of the arm and the bucket.
[0007]
However, in the swing type, the work front rotates (swings) not only in the vertical direction but also in the horizontal direction. Therefore, if the boom is tilted backward, the interference range between the boom and the upper cover increases, and the volume of the upper cover increases. And the required equipment cannot be stored in the upper cover. For this reason, conventionally, there has been a problem that the angle of tilting the boom backward has to be reduced or the vertical pin, which is the center of the swing, has to be extended forward, and the turning radius in the front minimum turning posture cannot be reduced.
[0008]
An object of the present invention is to provide a swing type excavator that does not have a complicated parallel link mechanism at the upper part of the work front, and a swing type excavator capable of minimizing a reduction in the volume of an upper cover and reducing a turning radius in a minimum front turning position. An object of the present invention is to provide a hydraulic excavator.
[0009]
[Means for Solving the Problems]
(1) In order to achieve the above object, according to the present invention, a lower traveling body, a revolving frame pivotally mounted on an upper part of the lower traveling body, and a horizontal pin centered on a vertical pin mounted on the revolving frame. A swing post rotatably mounted in the direction, a work front including a boom mounted rotatably in the vertical direction on the swing post, and a driver cab provided on one side in the width direction on the revolving frame. An upper cover that covers most of the pivot frame other than the operator's cab and accommodates equipment such as a prime mover, a hydraulic pump, and a tank, and the work front swings the boom to the maximum, The boom tilts rearward to the side of the cab when the front minimum turning position is closest to the cover, thereby reducing the turning radius in the front minimum turning position. In the swing type hydraulic excavator, a curved portion that allows the operation of the work front is formed at a front end portion of the upper cover, and the curved portion has a center axis at an axis of the vertical pin, and A swing type excavator is provided, wherein the excavator includes a concave surface having a shape along a locus drawn by a back surface of the boom when the work front is swung in the front minimum turning posture and forming a gap with the locus.
That is, when the boom is swung in the minimum swiveling position closest to the upper cover, the boom is attached to a swing post attached to the swivel frame around a vertical pin so as to be rotatable in the vertical direction. Is drawn, for example, in the shape of a substantially inverted cone having a central axis at the axis of the vertical pin. Therefore, if the boom is to be largely tilted rearward in the minimum turning posture, the boom and the upper cover will interfere with each other somewhere along the path. Here, in the present invention, by providing a curved portion formed at the front end portion of the upper cover with a concave surface having a central axis at the axis of the vertical pin, along the locus and forming a gap therewith. Even when the boom is tilted backward greatly in the minimum turning posture, the boom and the upper cover can be prevented from interfering with each other. Therefore, by turning the boom largely backward in the minimum turning posture, the turning radius in the front minimum turning posture can be reduced. Also, at this time, the reduction in the volume of the upper cover is minimized by the amount of the concave surface formed in the curved portion, so that it is possible to secure the storage of necessary equipment in the upper cover.
[0010]
(2) In the above (1), preferably, in the swing hydraulic excavator, the turning frame is formed to have a size capable of turning within a vehicle width of the lower traveling body or a diameter close to the vehicle width, A swing type excavator is provided, wherein the work front is configured to be capable of turning within a turning radius of the turning frame.
That is, the turning frame is formed to have a size that allows turning within the vehicle width of the lower traveling structure or within a diameter close to the vehicle width, and the work front is configured to be able to turn within the turning radius of the turning frame. In this case, the space of the upper cover is more restricted, which is more effective.
[0011]
(3) Further, in the above (2), preferably, in the swing type excavator, the boom of the work front is a two-piece boom having a lower boom and an upper boom, and one end of the work front is connected to the upper boom. A cross rod that is connected and changes an angle between the upper boom and the lower boom according to a swing angle of the lower boom, and the swing post has a rear protrusion that connects the other end of the cross rod. The curved portion further includes a first step portion provided at a lower end of the concave surface and forming a substantially constant gap with a locus drawn by a rear protruding portion of the swing post when the work front is swung. A swing type hydraulic excavator is provided.
That is, when raising the lower boom to fold the work front in order to take the minimum turning posture, the upper boom is a cross rod having one end connected to the upper boom and the other end connected to the rear protrusion of the swing post. Since the angle between the lower booms can be changed, a configuration in which the work front can be turned within the vehicle width of the lower traveling body or within a diameter close to the vehicle width can be easily realized. And, since the curved portion has the first step portion that forms a substantially constant gap with the locus drawn by the rear projecting portion during the swing, even when swinging in the minimum turning posture, the first step portion is formed. There is always a substantially constant gap between the rear projection and the rear projection, and these interferences can be avoided. Therefore, the work front can be turned within the vehicle width of the lower traveling body or within a diameter close to the vehicle width in the front minimum turning posture while securing the storage of necessary equipment in the upper cover.
[0012]
(4) Further, in the above (3), preferably, in the swing type excavator, the first step portion is formed continuously at a lower end of the concave surface and the first step portion is formed when the work front is swung. A substantially vertical curved surface that forms a substantially constant gap with the locus drawn by the rear end of the rear projecting portion of the swing post, and the substantially vertical curved surface is formed continuously on the work front side and swings the work front. Sometimes the swing post has a locus drawn by the lower end of the rear protruding portion and a substantially horizontal surface forming a substantially constant gap, and the substantially vertical curved surface has a center axis at the axis of the vertical pin, A free end of the substantially horizontal surface has an arc shape having a center axis at an axis of the vertical pin, and a swing type excavator is provided.
That is, when the boom is tilted rearward to the side of the driver's cab in the minimum turning posture, for example, the earth and sand attached to the bucket or the like accidentally falls on the curved portion of the upper cover, and at a stretch on the concave surface toward the vertical pin. There is a possibility that the swing post may be hindered in the vicinity of the vertical pin and hinder the rotation operation of the swing post, or may be hindered in the vicinity of the mounting portion of the lower boom to hinder the rotation operation of the lower boom. Therefore, a substantially vertical curved surface and a substantially horizontal surface are provided in the first step portion, and once the sediment that has slid on the concave surface is temporarily stored on the substantially horizontal surface, the swing post rotates in the circumferential direction. By scraping and removing the earth and sand, the vicinity of the mounting portion of the vertical pin or the lower boom can be protected from the earth and sand.
[0013]
(5) Further, in the above (4), preferably, in the swing type excavator, the height of the substantially horizontal surface near both ends in the circumferential direction is lower than that near the center in the circumferential direction. A swing type excavator is provided.
Thus, the earth and sand temporarily stored in the first step portion can be guided to both ends in the circumferential direction, so that the vicinity of the mounting portion of the vertical pin or the lower boom can be more reliably protected.
[0014]
(6) In the above (1), preferably, in the swing type excavator, the curved portion is provided at a middle portion in the height direction of the concave surface and has a substantially horizontal surface for securing a scaffold. A swing hydraulic excavator further comprising two step portions is provided.
That is, by utilizing the substantially horizontal surface forming the second step as a foothold for the worker, walk-through during maintenance can be realized, and workability can be improved.
[0015]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, an embodiment of a swing type excavator according to the present invention will be described with reference to the drawings.
FIG. 1 is a top view showing the entire structure of a swing type excavator according to the present embodiment, FIG. 2 is a side view as viewed from a direction A in FIG. 1, and FIG. 3 is a side view as viewed from a direction B in FIG. FIG. 4 is a partially transparent perspective view of the hydraulic excavator shown in FIG.
1 to 4, the hydraulic shovel according to the present embodiment includes a lower traveling body 2 having left and right crawler tracks 1L and 1R as traveling means, and a swivel mounted on the upper portion of the lower traveling body 2 so as to be pivotable. A frame 3, a swing post 4 attached to the revolving frame 3 so as to be rotatable in a horizontal direction around a vertical pin (not shown), and a swing post 4 attached to the swing post 4 so as to be rotatable in a vertical direction. A work front 5, a driver's cab 7 provided on the revolving frame 3 and having a seat 6, and an upper cover 8 covering most of the revolving frame 3 other than the driver's cab 7 are provided.
[0016]
The lower traveling body 2 includes a substantially H-shaped track frame 9, drive wheels 10L and 10R rotatably supported near the rear ends on both left and right sides of the track frame 9, and drive wheels 10L and 10R, respectively. Left and right running motors 11L, 11R to be driven, and rotating wheels rotatably supported near the front ends on both the left and right sides of the track frame 9 and rotated by the driving force of the driving wheels 10 via the crawler tracks 1L, 1R. (Idler) 12L, 12R, and a blade 14 for earth removal, which is provided on the front side of the track frame 9 so as to be able to move up and down and is moved up and down by a blade cylinder 13. A swivel bearing 15 is arranged at the center of the lower traveling body 2.
[0017]
The work front 5 includes a boom 16 that is a two-piece boom including a lower boom 16L and an upper boom 16U, an arm 17 rotatably connected to the upper boom 16U, and a bucket 18 rotatably connected to the arm 17. And a cross rod 19 having one end connected to the upper boom 16U and changing an angle between the upper boom 16U and the lower boom 16L. The lower boom 16L, the arm 17, and the bucket 18 are operated by a boom cylinder 20, an arm cylinder 21, and a bucket cylinder 22, respectively.
[0018]
Here, FIG. 5 shows a detailed structure of the swing post 4 to which the work front 5 is attached. 5A and 5B are a side view and a top view, respectively, of the swing post 4, and FIG. 5C is a front view as viewed from a direction C in FIG. 5A. 5 (a) to 5 (c) and FIG. 2, the swing post 4 rotates around the axis m with respect to the turning frame 3 through vertical pins (not shown) inserted into the holes 4a and 4b. It is possible. The swing post 4 is connected to a swing cylinder 23 provided on the revolving frame 3 via connection pins (not shown) inserted into the holes 4c and 4d. The work front 5 swings left and right by rotating the whole about the axis m.
[0019]
In addition, one end of the lower boom 16L is rotatably connected to the swing post 4 via a connecting pin (not shown) inserted into the holes 4e and 4f around the axis n. Furthermore, the bottom part of the boom cylinder 20 for operating the lower boom 16L is rotatably connected via a connecting pin (not shown) inserted into the hole 4g. At this time, the other end of the cross rod 19 whose one end is connected to the upper boom 16U via connection pins (not shown) inserted into the holes 4h and 4i provided in the rear protruding portion 4A is rotated around the axis l. To be rotatably connected to. Thereby, the cross rod 19 functions as a link member that regulates the front shape, and changes the angle between the upper boom 16U and the lower boom 16L according to the rotation angle of the lower boom 16L with respect to the turning frame 3. I have.
[0020]
Returning to FIGS. 1 to 4, a turning motor 24 for turning the turning frame 3 with respect to the lower traveling body 2 is disposed near the center of the turning frame 3. At this time, as shown in FIG. 1, the turning frame 3 is configured to be capable of turning within a diameter close to the vehicle width of the lower traveling body 2 (= a diameter slightly larger than the vehicle width).
[0021]
Further, when the boom 16 is swung up to the maximum and the boom 16 takes the minimum turning posture in which the boom 16 comes closest to the upper cover 8 (hereinafter simply referred to as the front minimum turning posture), the lower boom 16L is raised and the work front 5 is folded, so that the upper boom 16U The cross rods 19 respectively connected to the rear protruding portion 4A of the swing post 4 change the angle between the upper boom 16U and the lower boom 16L, whereby the boom 16 leans backward to a position on the side of the cab 7. Thus, the work front 5 is configured to be able to turn within the range of the turning radius of the turning frame 3, that is, within a diameter close to the vehicle width of the undercarriage 2. At this time, the position of the vertical pin (axial center m) inserted into the hole 4a, 4b of the swing post 4 is within the turning radius of the turning frame 3 as shown in FIG.
[0022]
The hydraulic actuators described above, that is, the blade cylinder 13, the swing motor 24, the boom cylinder 20, the arm cylinder 21, the bucket cylinder 22, the swing cylinder 23, and the left and right traveling hydraulic motors 11 are particularly detailed. Although not described in detail, it is driven by a known hydraulic drive device (for example, JP-A-7-189298 and JP-A-7-26592).
[0023]
On the other hand, the driver's cab 7 is provided on the left side of the turning frame 3 described above. The detailed structure of the cab 7 is shown in FIGS. 6 is a top view of the cab 7, FIG. 7 is a front view as viewed from a direction D in FIG. 6, and FIG. 8 is a side view as viewed from a direction E in FIG.
6 to 8, in front of the seat 6 in the cab 7, left and right traveling levers 25L and 25R for driving the left and right traveling hydraulic motors 11L and 11R of the lower traveling body 2, respectively, A swing pedal 26 for driving the swing cylinder 23 to swing the work front 5 and a front stay 27 for preventing the operator from falling forward are provided. On the left side of the seat 6, a side stay 28 and a side cover 29 for preventing the operator from falling to the left side are provided, and on the right side of the seat 6, a blade for driving the blade cylinder 13 to move the blade 14 up and down. A lever 30, a switch / monitor panel 31 on which various switches and monitors are arranged, and a fuel lever 33 for controlling fuel supply from a fuel tank 32 are provided. Left and right working levers 34L, 34R for driving the boom cylinder 20, the arm cylinder 21, and the bucket cylinder 22 to operate the lower boom 16L, the arm 17, and the bucket 18, respectively, are provided on both sides of the seat 6. Have been.
[0024]
The driver's cab 7 includes a roof 36 provided above the seat 6 and having a skylight 35, a rear wall 37 provided behind the seat 6, and a side wall 38 provided on the inner side (right side) of the seat 6. And an inclined wall 39 which is provided continuously to the side wall 38 and whose end on the work front 5 side reaches the front edge 7A of the cab 7 when viewed in plan. Further, near the upper end of the side wall 38, there is provided a concave portion 38a which is concave toward the inside of the cab 7. This prevents the vicinity of the connection pin 40 between the lower boom 16L and the upper boom 16U or the connection pin 41 between the cross rod 37 and the upper boom 16U from interfering with the side wall 38 in the front minimum turning posture. (See FIG. 2).
[0025]
Most of the rear wall 37, the side wall 38, and the inclined wall 39 are all formed of a transparent material, and are disposed substantially vertically. The inclined wall 39 has a substantially planar shape, and the side wall 38 has a substantially planar shape on the side of the inclined wall 39 except for the concave portion 38a, but has a curved surface on the rear wall 37 side, and the rear wall 37 has a curved surface. It is.
[0026]
4, the upper cover 8 has an engine 42, a hydraulic pump 43 driven by the engine 42, a fuel tank 32 for storing fuel of the engine 42, and a pressure of the hydraulic pump 43, as shown in FIG. A device such as a hydraulic oil tank 44 serving as an oil source is stored. At this time, the engine 42, the hydraulic pump 43, and the fuel tank 32 are disposed on the right side of the cab 7 in the upper cover 8, and the hydraulic oil tank 44 serving as a pressure oil source of the hydraulic pump 43 is connected to the upper cover 8 Inside the cab 7. The upper cover 8, which is a main part of the present embodiment, will be described with reference to FIGS.
[0027]
9 and 10 are a top view showing a detailed structure of the upper cover 8 and a perspective view showing a schematic structure of the upper cover 8. FIG. 11 shows a bending portion (described later) and a lower boom 16L in a front minimum turning posture. It is explanatory sectional drawing which shows the positional relationship of. In FIGS. 9 to 11 and FIG. 1, the upper cover 8 has a curved portion at the end portion on the side of the work front 5 to allow the operation of the work front 5 (in other words, to avoid interference with the work front 5). A part 45 is formed. The curved portion 45 is provided at the lower end of the concave surface 45A having a central axis at the axis m of the vertical pin of the swing post 4 (see FIG. 1), and provided at the lower end of the concave surface 45A. A first step 45B which forms a substantially constant gap with the locus drawn by the rear protruding portion 4A (see FIG. 11), and a substantially horizontal surface 45C1 provided at a height intermediate portion of the concave surface 45A and for securing a scaffold. And a second step portion 45C provided with
[0028]
The concave surface 45A has a shape (for example, a substantially mortar shape, see FIG. 11) along the locus drawn by the back surface of the boom 16 when the work front 5 is swung in the minimum front turning posture.
The first step portion 45B is formed continuously with the lower end of the concave surface 45A, and is substantially vertical which forms a substantially constant gap with the locus drawn by the rear protruding portion 4A of the swing post 4 when the work front 5 is swung. The curved surface 45B1 (see FIG. 11) and the curved surface 45B1 are formed continuously with the work front 5 side, and the locus drawn by the lower end of the rear protruding portion 4A of the swing post 4 when the work front 5 is swung is substantially constant. A substantially horizontal surface 45B2 (same as above) forming a gap.
The substantially vertical curved surface 45B1 has a shape having a central axis at the axis m of the vertical pin of the swing post 4. The substantially horizontal surface 45B2 has a free end in an arc shape having a central axis at the axis m of the vertical pin, and a height near the circumferential end portions 45B2l, 45B2r is close to a circumferential central portion 45B2m. Lower than.
[0029]
In addition, in addition to the above, the upper cover 8 is provided with an oil tank cover 46 as a cover for the hydraulic oil tank 44, an inspection cover 47 that opens and closes during maintenance, an oil supply hole 48 for replenishing the fuel tank 32 with fuel, and the like. ing.
[0030]
According to the present embodiment configured as described above, the following operations are provided.
That is, when the work front 5 is swung in the minimum turning posture in which the boom 16 is closest to the upper cover 8, the trajectory on the back of the boom 16 draws a trajectory having a central axis at the axis m of the vertical pin. Therefore, in the case where the boom 16 is to be largely tilted rearward in the minimum turning posture, the boom 16 and the upper cover 8 interfere with each other at some point along the path. Here, in the present embodiment, a curved portion 45 is formed at an end portion of the upper cover 8 on the work front 5 side, and the curved portion 45 has a center axis at the axis m of the vertical pin and follows the locus. And a concave surface 45A having a shape that forms a gap with the locus thereof is provided. Thereby, even if the boom 16 is tilted greatly backward in the minimum turning posture, the boom 16 and the upper cover 8 can be prevented from interfering with each other. At this time, for example, the soil that has fallen from the bucket 18 during a small turn tends to slip down due to the concave surface 45 </ b> A, so that there is also an effect that the accumulation of the earth and sand on the upper cover 8 can be reduced.
[0031]
Further, by providing the curved portion 45 with the first step portion 45B which forms a substantially constant gap with the locus drawn by the rear protruding portion 4A of the swing post 4 at the time of the swing, even when swinging in the minimum turning posture, There is always a substantially constant gap between the first step portion 45B and the rear projecting portion 4A, and these interferences can be avoided.
[0032]
Accordingly, the boom 16 can be largely tilted rearward at the time of the minimum turning posture by the above two interference prevention functions, so that the working front 5 is moved within the turning radius of the turning frame 3, that is, within a diameter close to the vehicle width of the lower traveling body 2. It can be pivotable.
[0033]
Further, when the boom 16 is tilted backward to the position on the side of the cab 7 in the minimum turning posture, for example, the earth and sand adhered to the bucket 18 and the like fall into the curved portion 45 carelessly, and face the vertical pin on the concave surface 45A. There is a possibility that the swing post 4 will be slid down at once and hinder the rotation of the swing post 4 by being pinched near the vertical pin, or hindered by the vicinity of the mounting portion of the lower boom 16L. Therefore, in this embodiment, by providing the substantially vertical curved surface 45B1 and the substantially horizontal surface 45B2 in the first step portion 45B, the earth and sand that has slid on the concave surface 45A is temporarily stored on the substantially horizontal surface 45B1. Thereafter, the earth and sand is scraped out and removed in the circumferential direction by the pivotal movement of the swing post 4, and the vicinity of the mounting portion of the vertical pin and the lower boom 16L can be protected from the earth and sand. Further, at this time, the height near the circumferential end portions 45B2l and 45B2r is lower than the vicinity of the circumferential center portion 45B2m, so that the sediment temporarily stored in the first step portion 45B can be removed from the circumferential end portions 45B2l. , 45B2r, so that the vicinity of the mounting portion of the vertical pin and the lower boom 16L can be more reliably protected.
[0034]
Furthermore, by utilizing the substantially horizontal surface 45C1 of the second step 45C as a foothold for the worker, a walk-through during maintenance can be realized, and workability can be improved.
[0035]
In the above, the decrease in the volume of the upper cover 8 is minimized by the concave surface 45A, the first step portion 45B, and the second step portion 45C formed in the curved portion 45. It is possible to ensure that necessary equipment is accommodated in the inside of the apparatus.
[0036]
In the above embodiment, the turning frame 3 can be turned within a diameter close to the vehicle width of the lower traveling body 2 (a diameter slightly larger than the vehicle width), and the work front 5 is turned in the minimum turning posture. It is configured to be able to turn within the turning radius of, but is not limited to this. That is, a hydraulic excavator in which the revolving frame 3 pivots within a diameter somewhat larger than the lower traveling body 2, a hydraulic excavator in which the revolving frame 3 can pivot within the vehicle width of the lower traveling body 2, or a work front 5 is a revolving frame. The present invention is also applicable to a hydraulic excavator capable of turning in a range slightly larger (closer to the turning radius) than the turning radius of the turning frame 3 and a hydraulic excavator in which the working front 5 can turn in a range somewhat larger than the turning radius of the turning frame 3. is there. Also in these cases, the original effect of the present invention that the turning radius of the work front 5 in the minimum turning posture can be reduced while minimizing the reduction of the volume in the upper cover 8 can be obtained. However, the space in the upper cover 8 is more restricted as the excavator in which the revolving frame 3 turns with a smaller diameter and the excavator in which the work front 5 can turn with a smaller diameter in the minimum turning position. So it is more effective.
[0037]
Further, in the above-described embodiment, the case where the so-called two-piece boom type boom 16 is provided has been described as an example. In this case, the same effect can be obtained.
[0038]
【The invention's effect】
According to the present invention, even when the boom is tilted backward greatly in the minimum turning posture, the interference between the work front and the upper cover can be avoided by the concave surface provided in the curved portion. Therefore, it is possible to reduce the turning radius in the front minimum turning posture while minimizing the decrease in the upper cover volume.
[Brief description of the drawings]
FIG. 1 is a top view showing the entire structure of a swing type excavator according to one embodiment of the present invention.
FIG. 2 is a side view seen from a direction A in FIG.
FIG. 3 is a side view as viewed from a direction B in FIG. 1;
FIG. 4 is a partially transparent perspective view of the hydraulic excavator shown in FIG. 1;
FIG. 5 is a side view, a top view, and a front view of the swing post shown in FIG. 1;
FIG. 6 is a top view of the cab shown in FIG. 1;
FIG. 7 is a front view as viewed from a direction D in FIG. 6;
FIG. 8 is a side view as seen from a direction E in FIG. 6;
FIG. 9 is a top view showing a detailed structure of an upper cover shown in FIG. 1;
FIG. 10 is a perspective view illustrating a schematic structure of an upper cover illustrated in FIG.
FIG. 11 is an explanatory cross-sectional view showing a positional relationship between a bending portion and a lower boom in a front minimum turning posture.
[Explanation of symbols]
2 Undercarriage
3 Swivel frame
4 Swing post
4A rear projection
5 Work front
7 cab
8 Top cover
16 Boom
16L lower boom
16U upper boom
19 Cross Rod
42 engine (motor)
43 Hydraulic pump
44 Hydraulic oil tank (tank)
45 curved part
45A concave
45B first step
45B1 Substantially vertical curved surface
45B2 Substantially horizontal surface
45B2l, r Both ends in the circumferential direction
45B2m Circumferential center
45C Second step
45C1 Substantially horizontal surface
m Vertical pin axis

Claims (6)

A lower traveling body, a revolving frame rotatably mounted on the upper part of the lower traveling body, a swing post mounted on the revolving frame so as to be rotatable in a horizontal direction around a vertical pin, and A work front including a boom rotatably mounted in the up and down direction, an operator cab provided on one side in the width direction on the revolving frame, and covering most of the revolving frame other than the operator cab, a motor, A hydraulic pump, an upper cover for storing equipment such as a tank, the work front swings the boom to a maximum, and when the boom is in a front minimum turning posture in which the boom is closest to the upper cover, the work boom is In a swing type excavator that is tilted backward to a position on the side of the cab, thereby reducing a turning radius in the front minimum turning posture,
A curved portion which allows the operation of the work front is formed at a front end portion of the upper cover, the curved portion has a center axis at the axis of the vertical pin, and the work front is in the minimum turning posture of the front. A swing-type hydraulic shovel comprising a concave surface having a shape that follows a locus drawn by the back surface of the boom when the boom is swung and forms a gap therewith. 2. The swing type excavator according to claim 1, wherein the turning frame is formed to have a size capable of turning within a vehicle width of the lower traveling body or within a diameter close to the vehicle width, and the work front is provided with the turning frame. A swing-type hydraulic excavator, which is configured to be capable of turning within a range of a turning radius. 3. The swing hydraulic excavator according to claim 2, wherein the boom of the work front is a two-piece boom having a lower boom and an upper boom, and the work front has one end connected to the upper boom and has a swing angle of the lower boom. 4. The swing post has a rear protruding portion connecting the other end of the cross rod, and the bending portion is provided at a lower end of the concave surface. A swing type hydraulic shovel, further comprising a first step portion provided and forming a substantially constant gap with a locus drawn by a rear protruding portion of the swing post when the work front is swung. 4. The swing type excavator according to claim 3, wherein the first step portion is formed continuously with a lower end of the concave surface, and a rear end of a rear protruding portion of the swing post is formed when the work front is swung. 5. A substantially vertical curved surface that forms a substantially constant gap with a locus to be drawn, and a rear protruding portion of the swing post that is formed continuously on the work front side of the substantially vertical curved surface and swings the work front. It has a locus drawn by the lower end and a substantially horizontal surface forming a substantially constant gap, the substantially vertical curved surface has a center axis at the axis of the vertical pin, and the free end of the substantially horizontal surface is A swing type excavator having an arc shape having a central axis at the axis of a vertical pin. 5. The swing type excavator according to claim 4, wherein the height of the substantially horizontal surface near both ends in the circumferential direction is lower than that near the center in the circumferential direction. 2. The swing hydraulic excavator according to claim 1, wherein the curved portion further includes a second step portion provided at a middle portion of the concave surface in a height direction and having a substantially horizontal surface for securing a scaffold. A swing type excavator characterized by the following.

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